The Collaborative International Dictionary
Pyrophoric \Pyr`o*phor"ic\, Pyrophorous \Py*roph"o*rous\, a. Light-producing; of or pertaining to pyrophorus.
Pyrophoric iron (Chem.), finely reduced iron, which ignites spontaneously on contact with air.
Douglas Harper's Etymology Dictionary
Wiktionary
a. 1 spontaneous ignite in air, especially when in a finely divided state 2 producing sparks, especially by friction 3 (''fire investigation'') Able to oxidize with expose to atmosphere oxygen at normal temperature.
WordNet
Usage examples of "pyrophoric".
Terran counterpart, as the latter used volatile fluids instead of resinous oils, and many Terran models depended on pyrophoric rare-earth surfaces rather than on flint.
It was on the old television that we got our first pyrophoric display of false positives, as metal around the dials and screen lit up and cable connecters turned the blue-white of thin milk.
As the iridescent silver whirlwind touched the surface of the Release Flame tiny glowing sparks picked out the edge, like the display of pyrophoric iron dropped from a tube.